/Engine/Source/Editor/MovieSceneTools/Public/TrackEditorThumbnail/TrackEditorThumbnail.h
Assign this thumbnail from a slate texture.
void AssignFrom ( [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [FSlateTextureData](API\Runtime\SlateCore\Textures\FSlateTextureData), ESPMode::ThreadSafe > InTextureData )